Pneumatic hammer.



E. C. MEISSNER. PNEUMATIU HAMMER. APPLIUATION FILED MAY 28. 1906.

Patented June 4, 1912-.

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strains rarari'r EEWARD C. MEISSNER, OF ST. L O'US, MISSOUR, ASSIGNOR TO. CHGAGfl'lllllUMTIC TOL CQMPANY, OF CHICAGO, JILLINOIS, A. CORPGRATION F NEW JERSEY.

PNEUMATICI HAMMER.

Specication of 'Letters Patent.

ieee. serial no. 319,095.

To all whom t may concern;

Beit known thatvl", EDWARD C. MEIssNER, a citizen of the United States, residing .at

USt. Louis, Missouri, have invented certain 4matic Hammers, of which the followingis a specification.

lfiled on. November 12,

new and useful Improvements in Pneurlhis invention relates .to pneumatic ham- 'mersand tocvertain features of constructionV of the pneumatic hammer which is shown" and described in an original applicltion 1900, Se1ial'-No.

36,212, of which applicationv the presenting; s

plication is adivision. v The' present invention relates to certaln advantageous features of construction and '4 operation and consists, rst, in the provision of a novel arrangement ,of exhaust `which supplemental to the main ,or regular eve haust, and second, in the provision "of novel means for Constantly admitting a restricted supply of thelive air into the rear end 'of the piston chamber.

In the drawings, Figure l is a longitudinal sect-ion `of a pneumatic hammer embodyA ing my invention; Fig. 2 a section of the rear end of the. cylinder and the handle socket and thefparts'therewithin, which section is enlarged as compared with `the-scale' of Fig. l; Fig. 3 a .section of the valve alone; Fig. 4 a section on line of Fig.

l; and Fig. 5 a sectionv on line 5-5 of Fig. 1.

Referring to the embodiment of my invention as herein shown the hammer com- .prises a. grasping handle 1, a barrel or cyl` inder 4 secured thereto in suitable vmanner as by means of a coupling sleeve 6,. a piston 5 arranged to reciprocate in the cylinder,

a valve bushing 2 in .the socket portion of the grasping handle, a valve 3 within'the bushing together with ports and passages governed by said valvejfor controlling the admission andexhaust ofpressure to and from opposite ends ofthe cylinder for the' reciprocat-ion of the ofthe hammer.y The bushing piston in the operation 2j forms the `chamber in..

' Patented June 1i, iliil. `@riginal application filed ovmber 1'2, 1900, Serial'qo. 36,212. Divided and this application iled May 28,

of portsand groove12 and is provided intermediate of its length, beginning at a p ol'nt near its forward end, witha series of cucumferential ,grooves and ports marked Y respectively 13 14,15, 16, 17 and 18, which are arranged to register either with each otherl by means of grooves inthe valve or to register with passages in the handlesocket .as hereinafter explained. T he. groove and ports 13 are always exposed tothe live air which'is admitted from the source of supply past the throttle valve 43 and through the Y passage 19 in the handle, such passage being Y extended longitudinally of the `handlesocket (as shown in dotted lines in Fig. 2)A

esto emerge in the interior of such handie socket in position to lregister with the groove and ports 13. The ports 15 are in position to register with the rear end of a passage 2O extending longitudinally of the .handle-socket and also of the cylinder and communicating with the forward end of the piston chamber through a port 21. The eX haust for the rear end of the piston chamber is in the form 'of a groove 28 which communicates with a passage 22 extending through the rear end of the cylinder and theA forward end of the handle-socket and vterminating in such handle-socket in a position to register with the groove and ports 17 in .the bushing. This exhaust port or groove 23 is located forward of the valve-bushing and at such a distance therefrom as to per mit the piston on its'rearward 'or return stroke to close such exhaust port or groove 23 before the end of such stroke and to thereupon compress the air between'the rear end of the piston and the forward end of the valve with the result that such trapped air is compressed to a degree in excess of the normal or working pressureof the live air and caused to shift the valve rearwardly in a manner herelnafter more particularly explained. Thefexhaust'fgroove 23 and eX* haust passage 22 which leads to the groove or4 series of ports 17 are arranged to be vplaced in. communication with the main or regular exhaust ports andpassages 24 in the handle socket by means of the valve 3,

with the result that when the valve is in one position, in the present instance its forward position, the ports 17.are in communication with said' exhaust port and passage 24. 4

The valve 3 is provided with two circumferential grooves 25 and. .26, the formenof which is arranged to control the admission and release of the compressed air to and from the forward end of the piston chamber, while the other groove 26 is arranged to control the exhaust of air pressure from the rear ,end of such piston chamber, the admission of air pressure to such rear end of piston chamber being controlled by the short end of the valve itself. This valve is of the differential type andin the present instance the larger pressure area is at the rearward end thereof, while the smaller pressure area is at the forward end and exposed to the rearward end of t-he piston chamber. As herein shown, the valve is made differential by the provision of an annular flange 27 at the rearward end thereof and to accommodate such enlarged end of the valve, the valve bushing 2 is counterbored at its rearward end for a distance substantially equaling the extent of travel or reciprocation of the valve, the forward stroke or movement of such valve being limited by the annular shoulder 28 .at the'bottom or end of such counterbore. The rearward end of the valve bushing is provided with a cap Q9 which closes said bushing with the excep-4 tion of a series of ports 30, which are arranged to communicate with the rearmost port or ports 12 in the valve bushing. 'The port 12 communicates with a port and passage 31 extending through the handle socket and longitudinally through the wall of the barrel or cylinder to a point intermediate the length of the latter and communicating with the piston chamber through a pfort 32, which is uncovered by the piston 5 so as to communicate with the 'piston chamber in the rear of the piston at a time just prior to the completion of the forward stroke of such piston and also to communicate with the forward end of suoli piston chamber infront of the piston after the latter has moved rearward butbefore the same has completed its rearward stroke. A vent or bleed opening 33 to the atmosphere is formed 1n the handle of the socket to permit of the free admission and exhaust of pressure in the counterbore in front of the annular flange Q7 on the valve.

The front end of the cylinder or barrel is arranged to receive a sleeve or bushing into which, in practice, is inserted t-heI shank of the working tool which in' the present instance is shown as a button or rivet-set 34, whose shank lits snugly within the sleeve or bushing 35. Inasmuch as it is desirable in a riveting hammer to have the riiI t-set removably connected with the cylinder so as' to practically form a part thereof when in use but at the Sametime to provide for sumcient play or longitudinal movementof one with respect to the other, I provide a clip device which, as shown7 comprises a pair of substantially semi-circular pieces 38, preferably of sheet metal, which are provided at their rearward ends with inturned flanges 37 adapted to tit in a groovel 86. This groove is here formed in the sleeve or bushing 35, inasmuch as the 'same projects beyond and in line with the front end of the barrel or cylinder-v proper, such bushing however, being practically a component part of the cylinder. The semi-circular pieces or sections 38 are held or clamped in place with a yielding pressure by means of a resilient splitring 39 of sheet metal which lits in groove Ll() provided therefor on the outer surfaces of said pieces 38, whereby said pieces constitute clamping jaws for holding the rivet-set in operative posit-ion at the front end of the cylinder. In order to provide for'the relative adjustment longitudinally between lsuch rivet-set and the cylinder, I provide such' jaws on their inner faces with a circumferential,groove al and the rivet-set with an -annular rib or flange 42 movable longitudinally in said groove. The rib and grooves above described are preferably beveled to facilitate the removal of the clip device and thereby facilitate the insertion and removal of the' rivet-set or other tool. The shank of the rivet-'set fits into the sleeve or bushing suHiciently tightto insure the return of the piston, but the rib 4l2 and groove 4l are arranged to permit a slight end-wise or longi-v tudinal movement of the rivet-set'in rela'- tion to the cylinder. g

In addition to the main or regular ex- 'haust through the portand passage 24 in the handle socket, I provide the hammer with ai supplemental exhaust port which is independent of the main or regular exhaust haust the air pressure at'the front end of the piston chainber in advance of the piston. By the provision of this supplemental e'X- haust port, which is thus capable of eX- hausting the air pressure directly to the atmosphere from the pistonchamber on opposite sides of the piston, the exhaust' of the' air pressure at the proper times is facilirfa I H. MELLING.

COMBINED ROUTER AND DIE SINKER.

APPLIGATION FILED JUNE zo, 1911.

Patented June 4, 1912.

4 SHEETS--SHBET 1.

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